In light-emitting apparatuses including LEDs (light-emitting diodes), from the viewpoint of thermal resistance and heat dissipation, boards made of a metal such as aluminum are widely used for mount boards onto which LEDs are mounted. For example, Japanese Unexamined Patent Publication No. S55-132083 describes a light-emitting diode board constituted by an aluminum support, an alumite layer placed thereon, a transparent insulating thin layer on the alumite layer and a layer of printed wiring on the insulating layer, the layer of printed wiring having a light emitting diode attached thereon. Japanese Unexamined Patent Publication No. 2007-129053 describes a light-emitting apparatus including an alumite-treated aluminum plate support, a printed circuit board attached thereon provided with an electrically conductive pattern formed on the board and an opening, and an LED chip mounted on the support inside the opening.
In addition, Japanese Unexamined Patent Publication No. 2007-194385 describes a semiconductor light-emitting apparatus including a silicon substrate, an insulating silicon oxide film formed thereon, a bonding layer made from Ti (titanium) or Cr (chromium) on the insulating film, a barrier metal layer made from Ni (nickel) or Pt (platinum) or Pd (palladium) on the bonding layer, a silver alloy layer made on the barrier metal layer, a semiconductor light-emitting element electrically connected to the silver alloy layer.